Friday 1 April 2005 18.38 EST
First published on Friday 1 April 2005 18.38 EST

One way in which museums and galleries often try to secure high visitor numbers for exhibitions is by using such words as "gold" and "treasure" in the titles of their blockbuster shows. And yet there is something in our culture that resists taking treasure seriously. There is a protestant feeling that treasure is reprehensible, and it is with a shudder that many a non-believing protestant (that is, a protestant by culture rather than by religious education and observance) passes a cathedral treasury in which, perhaps, saints' bones are to be found in ancient reliquaries.

That same shudder, by unconscious extension, greets the opportunity to examine the secular treasures of the courtly palaces. If we are told of some ruler of a past era that he spent his wealth on the accumulation of a great collection of paintings and sculptures, that sounds to us like a man who had his priorities right. If we are told, by contrast, that he was obsessed with rare shells and rock crystals, which he had set in gold mounts, encrusted with precious and semi-previous stones, that strikes us more like the activity of a greedy and frivolous eccentric.

The art of such treasuries suffers also, to a terrible degree, from poor display - meaning that too much of it is shown, crammed haphazardly on to the shelf, and you have to be an expert to sort out the good from the indifferent. But this is an area where real expertise is confined to a very small number of people in the whole world. In some cases you will find that there is only one great specialist. How can the public, coming on such objects often for the first time, be expected to exercise fine discriminations?

In Dresden, there survives the Treasury Museum of the Prince Electors of Saxony - not the building, the Green Vault, which was once famous throughout Europe, but the collection of the Green Vault, which remains today, as the catalogue claims on its behalf, the most magnificent of its kind. Selections of its treasures have been shown around the world, and last year a new modern gallery was opened in the Residential Palace in Dresden.

Everything is well done, but the key points are that the selection is admirable, and one can take it as read that the objects being shown are the finest in their class. Also the modern vitrines, which have to keep their contents securely, preserve them in an appropriate climate and make them sparklingly visible, are properly designed. The effect on the crowd, during the blizzards of a few weeks ago, was palpable. Of course any of the treasures of Dresden that have survived the bombing have an enhanced interest, simply through having survived. But it was instructive to see what elegant modern display can do.

The earliest Kunstkammer in Dresden, in the latter part of the 16th century, was not part of the public princely rooms. It was a private space in which the prince could pursue an interest in technology. Of the 9,586 objects listed in the first inventory, more than 7,000 were craftsmen's tools and machines. Four hundred were scholarly instruments (astrolabes and so forth) and clocks. Of course such tools and instruments were themselves embellished so as to be objects of beauty in their own right. But they could be used. Right up to the 18th century, when the Kunstkammer tradition becomes hard to trace, you find evidence of the noble pursuit of certain crafts - lathe work and carving, for instance. The catalogue tells us that "Objects turned, carved, or embossed by people of high rank were termed memorabilia."

The earliest art objects were designed for (using the word properly) "disinterested pleasure": they were, for instance, drinking vessels which would never have been used for drinking, because the bowls were made from nautilus shells or ostrich eggs. Wonders of nature (curiously shaped corals, rhinoceros horns the colour of thick, dirty toenails, extremely hard woods such as fruit-stones which would take very fine carving) were transformed by the most elaborate of settings.

The ostrich eggs end up as drinking vessels that look like ostriches. A cherry pit, carved with 185 faces, is the gem in a pendant where you would normally expect a precious stone. A bizarrely shaped natural lump of gold ore (an object of admiration, in miniature, much like the scholars' stones of the Far East) becomes a Mount Calvary for a crucifixion group. And irregularly shaped pearls were used again and again in jewellery set with gold and enamel, to represent, for instance, the torso or the head of a figure.

The taste for the irregular object as found in nature went side by side with the study of regular objects (polyhedrons) and for the finely calculated vessels made of turned ivory. Special value was attached to the work of the court turners, who designed their own instruments and whose art "was the result of a perfect interplay of applied mathematics and advanced mechanical technology". In the late 16th century both the Prince Elector August and his son Christian I worked at such lathes, making no doubt such useless objects as the three-lidded goblets on display in Dresden. But the applied mathematics had its uses elsewhere: such rulers could draw their own maps.